I am having this same problem. I was repairing the game since I couldn't see some names or I just found empty bubbles when trying to grill or something inside the game.
When I started downloading the new expansion pack, some MBs after it finished it (0,10 left to 1,50 gb), zclient and zlorigin crashed all of a sudden. I reopened it and tried to resume download, but it kept crashing.
I reinstalled everything, following the steps as you did, it resumed downloading, but it keeps closing all of a sudden and without reason.
I don't know what else to do.